An analog-to-digital converter (ADC) is usable to convert analog signals to digital signals. There are a variety of ADC architectures, such as pipelined, flash, Sigma-Delta, and successive approximation register (SAR). In some applications, an achievable conversion resolution of an ADC is limited by for example thermal noises, electrical noises, and/or mismatch of various electrical components of the ADC. For example, in some SAR ADC applications, the conversion resolution of an SAR ADC depends on the noises and accuracy of an SAR comparator of the SAR ADC. In some applications, the SAR comparator is configured to consume more power and/or occupy a greater area in order to obtain improved conversion resolution.